The widow of conservative activist Charlie Kirk pledged Friday to uphold her late husband’s work, after U.S. authorities announced they had captured the man suspected of assassinating him.

Investigators had appeared to be making slow progress in the hunt for whoever gunned down Donald Trump's close ally, until they released security camera images of a young man.

"We got him," Utah Governor Spencer Cox told a news conference Friday, identifying the suspect as Tyler Robinson, 22, who had reportedly been confronted by his father over the pictures and then turned in.

The 31-year-old Kirk was hit by a single bullet while addressing a large crowd at Utah Valley University in the town of Orem on Wednesday.

Kirk was an electrifying presence on the U.S. right, with a huge young following that helped Trump win the election last November.